Bolted connector



Jan. 17, 1967 w, WHALEN 3,298,072

BOLTED CONNECTOR Original Filed Dec. 12. 1963 INVENTOR. B WILLIAM WHALEN zw/ /fl iz ATTORNEY United States Patent Office 3,298,072 BOLTED CONNECTOR William T. Whalen, Norwalk, Conn., assignor to Burndy Corporation, a corporation of New York Continuation of application Ser. No. 330,026, Dec. 12, 1963. This application June 10, 1965, Ser. No. 467,812 2 Claims. (Cl. 24-125) This is a continuation of application Serial No. 330,026, filed December 12, 1963, now abandoned. v

This invention relates generally to U-bolt connectors known also as split, slotted, or bifuncated bolts, and more particularly to a pressure bar used in such a device for compressing therein the conductors, wires, or other parts which are to be clamped together. In general, a nut is threaded to the outer surface of the legs of the bolt for urging the pressure bar against wires or parts positioned between the legs. The pressure bar is rotatably mounted to the nut, to permit the nut to rotate on the bolt while it linearly advances the pressure bar. This avoids rotary contact between the bar and the clamped parts. In most applications, the pressure bar is assembled to the nut by an extension of the bar which forms a nut retainer.

The bolt, nut and pressure bar are preferably made of high strength metal to withstand the forces developed in use. In an electrical connector, the higher the pressure applied, the better the electrical contact between the conductors being joined. That is, high pressure lowers the electrical resistance of the joint and results in higher electrical joint efficiency.

It is an object of the present invention to provide a combination of nut, pressure bar and retainer that is sufiiciently strong to withstand the required pressures, but which is lighter in weight than a conventional all-metal combination.

These and other objects and features of this invention will become more apparent by reference to the following description taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a partially sectioned side elevation view of a U-bolt connector provided with a novel pressure bar and nut retainer in accordance with this invention;

FIGURE 2 is a transverse sectional view of the same taken in the plane 2-2 of FIGURE 1;

FIGURES 3, 4 and 5 are side, end, and bottom views respectively of a modified form of pressure bar; FIG- URES 6 and 7 are side and end views of a modified form of retainer used to couple the modified pressure bar of FIGURE 3 to the nut.

Now, referring more in detail to the drawing, it may be seen that reference numeral 10 designates generally a U-bolt connector having a pair of parallel extending legs 12 and 14 which are threaded on their outer surfaces, as at 20, to receive a threaded nut 22. A pressure bar 24, disposed between legs 12 and 14 and beneath nut 22, is provided with extending wing portions 26 and 28 which engage and receive forces applied by nut 22. As the nut is axially advanced along the legs by screw thread rotation, the force of the advancement is transmitted through pressure bar 24 to parts such as wire conductors 16 and 18 disposed between legs 12 and 14 which are thus clamped between the bar and head portion of the U-bolt.

Instead of a unitary, all-metallic pressure bar having a portion adapted to be manually deformed or bolted to secure the nut thereto, I employ a pressure bar in combination with a light-weight non-metallic retaining base member 30 secured thereto.

The pressure bar and base are provided with tongue 32 and complementary groove 34, respectively (shown in FIGURE 2), which may be dimensioned for forcible engagement or otherwise secured in position to interlock the one to the other.

3,298,072 Patented Jan. 17, 1967 The base is provided with a pair of outwardly extending wings 36 which project through and beyond the nut 22, each of which includes a detent shoulder 38 spaced from the pressure bar 24 by a distance at least equal to or slightly greater than the axial length of the nut. Thus when the wings 36 of the base 30 are extended through the central opening of the nut 22, and the pressure bar 24 is positioned in the groove 34, the projections 38 are resiliently snapped into position on the upper surface 40 of the nut, to secure and make a unitary assembly of nut and pressure bar.

The length of the base 30 along the side, as shown in FIGURE 1, is less than the inner diameter of the nut opening, and the thickness is slightly less than the space between the bolt legs, to permit the nut to be rotated into position on the legs of the U-bolt, while the pressure bar is driven linearly towards the conductors. The nut however, directly compresses the pressure bar into clamping engagement with the conductors, so that no pressure is applied to the base. The base therefore can be made of low strength material such as any well known plastic.

In the modifications shown in FIGURES 3 to 7 the pressure bar 24a is provided with an integral rivet 32a where it may be upset in conventional rivet fashion to form a permanent attachment between bar and base. To assure proper alignment of the two during and after assembly, the bar may be provided with recesses 51 formed to engage mating ribs or projections 52 on the base.

If the retainer base 30a is made of highly resilient plastic, such as nylon, the wings 36a may be given considerable flexibility which may be increased by making the base hollow, as at 42, thus permitting the pressure bar to be permanently attached to the base, and the base retained to the nut by flexing back the wings 36a until they pass through the opening of the nut.

The base and bar of FIGURES 3-7 are otherwise numbered similarly to FIGURES l and 2 but with corresponding parts denoted by an added a.

The U-bolt, pressure bar, and nut may be made of forged or cast bronze, or silicon bronze, or other hard metal which does not deform easily and which possesses a high tensile strength.

The base is made of non-metallic material to reduce its weight and expense. If made of synthetics, plastics, or similar materials, it may also have the added advantages of being non-conductive, non-corrosive and non-magnetic.

The result is a light weight combination of nut and pressure bar that is more economical, easier to use and remove in the field, and permits greater interchangeability than previous types.

The invention has thus been described but it is desired to be understood that it is not confined to the particular forms or usages shown and described, the same being merely illustrative, and that the invention may be carried out in other ways without departing from the spirit of the invention; therefore, the right is broadly claimed to employ all equivalent instrumentalities coming within the scope of the appendent claims, and by means of which objects of this invention are attained and new results accomplished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to obtain these objects and accomplish these results.

Iclaim:

1. A U-bolt connector having a pressure bar, a nut, and a non-metallic retainer member movably coupling said pressure bar to said nut;

said retainer member comprising a substantially U- shaped unitary body portion of resilient material including a pair of integral resilient legs extending therefrom;

said pressure bar including a projecting portion having a discontinuitythereon for interlocking with said retainer member; a

said retainer member including a cavity in said resilient body portion having a discontinuity therein for receiving and interlocking with said projecting portion of said pressure bar; the said resilient legs of said retainer member each including a free end and an outwardly extending detentv shoulder proximate said free end for interlocking.

' comprise a transversely extending groove adapted to receive said tongue element and to resist separation there-' from in the direction in which pressure is transmitted by said pressure bar.

References Cited by the Examiner UNITED STATES PATENTS 2,816,274 12/ 1957 Barlow. v

v FOREIGN PATENTS 1,106,787 12/1955 France. 1,142,941 9/1957 France.

BERNARD A. GELAK, Primary Examiner. 

1. A U-BOLT CONNECTOR HAVING A PRESSURE BAR, A NUT, AND A NON-METALLIC RETAINER MEMBER MOVABLY COUPLING SAID PRESSURE BAR TO SAID NUT; SAID RETAINER MEMBER COMPRISING A SUBSTANTIALLY USHAPED UNITARY BODY PORTION OF RESILIENT MATERIAL INCLUDING A PAIR OF INTEGRAL RESILIENT LEGS EXTENDING THEREFROM; SAID PRESSURE BAR INCLUDING A PROJECTING PORTION HAVING A DISCONTINUITY THEREON FOR INTERLOCKING WITH SAID RETAINER MEMBER; SAID RETAINER MEMBER INCLUDING A CAVITY IN SAID RESILIENT BODY PORTION HAVING A DISCONTINUITY THEREIN FOR RECEIVING AND INTERLOCKING WITH SAID PROJECTING PORTION OF SAID PRESSURE BAR; THE SAID RESILIENT LEGS OF SAID RETAINER MEMBER EACH INCLUDING A FREE END AND AN OUTWARDLY EXTENDING DETENT SHOULDER PROXIMATE SAID FREE END FOR INTERLOCKING WITH SAID NUT. 